Construction on the Rironi–Mau Summit Highway continues, enhancing connectivity between Nairobi and Nakuru. The highway is being upgraded into a four-lane dual carriageway to improve traffic flow, safety, and regional trade along the Northern Corridor.

The Rironi–Mau Summit Highway reflects Kenya’s broader investment in modern expressways. Similarly, the Nairobi-Thika Expressway, set to start construction in September 2026, will ease congestion and improve mobility across Nairobi’s northern and western corridors. Details on the Thika-Westlands Expressway project are covered in our dedicated report.

Current Status

Sections of the Rironi–Mau Summit Highway are already under construction, with earthworks and drainage systems underway. Progress continues despite seasonal weather challenges, and contractors aim to complete major sections by mid-2027. Preparatory works for interchanges, grade separations, and safety features are ongoing, ensuring adherence to design and environmental standards.

Economic and Social Impact

The highway upgrade is expected to reduce travel times, enhance road safety, and create employment during construction. Improved connectivity will stimulate economic activity along the corridor and strengthen freight transport efficiency across the Northern Corridor.

Rironi-Mau Summit Highway Construction Project Factsheet

Project Name: Rironi–Mau Summit Highway Upgrade
Location: Nairobi–Nakuru Corridor, Kenya
Estimated Cost: $2 Billion
Project Model: Public-Private Partnership (PPP)
Scope: 175 km four-lane dual carriageway upgrade with interchanges and grade separation
Construction Start: August 2025
Expected Completion: Mid-2027

Contractors and previous agreements:

• Previous agreement: in the previous agreement, a concession agreement was signed with a consortium of French firms under Rift Valley Connect. This consortium comprised of Vinci Highways SAS, Meridiam Infrastructure Africa Fund, and Vinci Concessions SAS. This agreement was for a 30-year concession to design, build, finance, operate, maintain, and transfer the highways.
• Termination of the previous agreement: unfortunately, the Kenyan government terminated the agreement with the French consortium. This was as a result of a contractual dispute and disagreement on terms. The Kenyan government is expected to pay a Ksh6.2 billion contractual obligation settlement.

Current bids:

• China Road and Bridge Corporation (CRBC) in a joint bid with the National Social Security Fund (NSSF).
• Shandong Hi Speed Road and Bridge International Engineering Company.

Rironi-Mau Summit Highway Construction Commencement and Completion Date

“The highway project is expected to start in August.We have come to an agreement with the contractors to speed up the project and finish it by the year 2027. However, if not, they should have done a substantial portion of the project of it by that time,” he said.

Also read: Kenya’s 170-Kilometer Nakuru-Nairobi Highway Construction to Commence in July

The President made these remarks at an event in which he hosted a delegation of leaders from Nakuru County at State House, Nairobi, on Wednesday.

The attendees of the event included Nakuru Governor Susan Kihika, Trade and Investments Cabinet Secretary Lee Kinyanjui, and other leaders.

Number of Lanes on the Highway

President Ruto elaborated that the Rironi-Mau Summit Road will consist of four lanes from Rironi to Naivasha town. Additionally, it will consist of improvements on the Maai Mahiu-Naivasha road.

Also read: Kenya’s €1.3 Billion Nairobi-Nakuru Dual-Carriageway Deal to be Awarded to a Chinese Contractor

Lastly, the road will eventually expand to six lanes from Naivasha town to Nakuru City. This is in order to adequately accommodate the high volume of traffic on this route.

Also read: Kenya to Secure Multi-Billion Loan for the Construction of the 124-kilometre Kenya-Tanzania Road